Turbulent Drag Reduction on an Aircraft Wing

The aim of the present work is to reduce the turbulent drag induced on a supercritical aircraft wing at commercial flight scale conditions of Reynolds number and Mach number by using jets installed on the upper and lower surface of the wing. The present method is an active technique of viscous drag reduction. To the best of author’s knowledge, no such control technique has been explored at such conditions. The analysis considers jets in the stream-wise and span-wise direction incorporated on suction and pressure surfaces of the wing which tend to form a pair of colliding-jets in the span-wise direction. The efficacy of the control technique has been checked for jets with various emerging mass flux and inclination angle of the streams. The governing equation of continuity, RANS (using Spalart Allmaras as turbulence model) and the energy have been solved numerically using the commercial package Fluent®. The mechanism behind the control technique is the lifting of the boundary layer which brings about a reduction in the skin-friction component of the drag and the cross-diffusion of the near-wall streaks which brings about a decrease in the turbulent kinetic energy and hence viscous drag. Role of vorticity variation will also be explored.